From 8b07f20e582aca4d9b04ebebdc0ad5d27c0677e5 Mon Sep 17 00:00:00 2001
From: David Wake <6890281+daviddotcs@users.noreply.github.com>
Date: Sun, 10 Apr 2022 18:09:52 +0800
Subject: [PATCH] Add extension to simplify negating an
 IncrementalValueProvider<bool>

---
 .../IncrementalValueProviderExtensions.cs                | 9 +++++++++
 src/SafeRouting.Generator/RouteGenerator.cs              | 5 +----
 2 files changed, 10 insertions(+), 4 deletions(-)
 create mode 100644 src/SafeRouting.Generator/IncrementalValueProviderExtensions.cs

diff --git a/src/SafeRouting.Generator/IncrementalValueProviderExtensions.cs b/src/SafeRouting.Generator/IncrementalValueProviderExtensions.cs
new file mode 100644
index 0000000..0af1b96
--- /dev/null
+++ b/src/SafeRouting.Generator/IncrementalValueProviderExtensions.cs
@@ -0,0 +1,9 @@
+using Microsoft.CodeAnalysis;
+
+namespace SafeRouting.Generator;
+
+public static class IncrementalValueProviderExtensions
+{
+  public static IncrementalValueProvider<bool> Not(this IncrementalValueProvider<bool> source)
+    => source.Select(static (x, _) => !x);
+}
diff --git a/src/SafeRouting.Generator/RouteGenerator.cs b/src/SafeRouting.Generator/RouteGenerator.cs
index aa75527..68dae9e 100644
--- a/src/SafeRouting.Generator/RouteGenerator.cs
+++ b/src/SafeRouting.Generator/RouteGenerator.cs
@@ -28,10 +28,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
       var isSupportedLanguageVersionProvider = languageVersionProvider
         .Select(static (x, _) => x >= LanguageVersion.CSharp8);
 
-      var isUnsupportedLanguageVersionProvider = isSupportedLanguageVersionProvider
-        .Select(static (x, _) => !x);
-
-      context.RegisterConditionalOutput(isUnsupportedLanguageVersionProvider, static context =>
+      context.RegisterConditionalOutput(isSupportedLanguageVersionProvider.Not(), static context =>
       {
         context.ReportDiagnostic(Diagnostics.CreateUnsupportedLanguageVersionDiagnostic());
       });